A part mounting device for mounting a vehicular utility part in a receiving member such as a ceiling member has been known. Such a part mounting device includes a cover member, a part housing portion included in the cover member, and legs arranged around the part housing portion. The part housing portion is configured such that a part is arranged directly on a rear surface of the cover member.
When the part mounting device is mounted in the receiving member, the legs and the part housing portion are inserted in a through hole of the receiving member while the legs being elastically deformed and projections of the legs are fit on a hole edge of the through hole. Thus, the part mounting device is mounted in the receiving member.
The part housing portion and the legs arranged around the part housing portion that are included on the rear surface of the cover member are necessary to be inserted in the through hole to mount the part mounting device in the receiving member. Therefore, a size of the through hole is increased and accordingly, a size of the cover member disposed to cover the through hole is also increased. The size of the cover member that is disposed on a vehicular interior side surface of the receiving member is increased. This may deteriorate an appearance of an interior of a vehicle.